From patchwork Mon Nov 19 12:54:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tzvetomir Stoyanov X-Patchwork-Id: 10759773 Return-Path: Received: from mail-eopbgr810089.outbound.protection.outlook.com ([40.107.81.89]:53856 "EHLO NAM01-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728933AbeKSXR5 (ORCPT ); Mon, 19 Nov 2018 18:17:57 -0500 From: Tzvetomir Stoyanov To: "rostedt@goodmis.org" CC: "linux-trace-devel@vger.kernel.org" Subject: [PATCH 12/34] tools/lib/traceevent: Man pages for tep_print_field(), tep_print_fields(), tep_print_num_field() and tep_print_func_field() Date: Mon, 19 Nov 2018 12:54:22 +0000 Message-ID: <20181119125357.19449-13-tstoyanov@vmware.com> References: <20181119125357.19449-1-tstoyanov@vmware.com> In-Reply-To: <20181119125357.19449-1-tstoyanov@vmware.com> Content-Language: en-US MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org List-ID: Content-Length: 6354 Create man pages for tep_print_field(), tep_print_fields(), tep_print_num_field() and tep_print_func_field() as part of the libtraceevent APIs. Updated description of functions in event-parse.c Signed-off-by: Tzvetomir Stoyanov --- .../libtraceevent-field_print.txt | 120 ++++++++++++++++++ tools/lib/traceevent/event-parse.c | 4 +- 2 files changed, 122 insertions(+), 2 deletions(-) create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-field_print.txt diff --git a/tools/lib/traceevent/Documentation/libtraceevent-field_print.txt b/tools/lib/traceevent/Documentation/libtraceevent-field_print.txt new file mode 100644 index 000000000000..3a9372ba1102 --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-field_print.txt @@ -0,0 +1,120 @@ +libtraceevent(3) +================ + +NAME +---- +tep_print_field,tep_print_fields,tep_print_num_field,tep_print_func_field - Print the field content. + +SYNOPSIS +-------- +[verse] +-- +*#include * +*#include * + +void *tep_print_field*(struct trace_seq pass:[*]_s_, void pass:[*]_data_, struct tep_format_field pass:[*]_field_); +void *tep_print_fields*(struct trace_seq pass:[*]_s_, void pass:[*]_data_, int _size_, struct tep_event pass:[*]_event_); +int *tep_print_num_field*(struct trace_seq pass:[*]_s_, const char pass:[*]_fmt_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, int _err_); +int *tep_print_func_field*(struct trace_seq pass:[*]_s_, const char pass:[*]_fmt_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, int _err_); +-- + +DESCRIPTION +----------- +These functions print recorded field's data, according to the field's type. + +The _tep_print_field()_ function extracts from the recorded raw _data_ value of +the _field_ and prints it into _s_, according to the field type. + +The _tep_print_fields()_ prints recorded values of all _event_'s fields. It +iterates all fileds of the _event_, and calls _tep_print_field()_ for each of +them. + +The _tep_print_num_field()_ function prints a numeric field with given format +string. A search is performed in the _event_ for a field with _name_. If such +field is found, its value is extracted from the _record_ and is printed in the +_s_, according to the given format string _fmt_. If the argument _err_ is non-zero, +and an error occures - it is printed in the _s_. + +The _tep_print_func_field()_ function prints a function field with given format +string. A search is performed in the _event_ for a field with _name_. If such +field is found, its value is extracted from the _record_. The value is assumed +to be a function address, and a search is perform to find the name of this +function. The function name (if found) and its address are printed in the _s_, +according to the given format string _fmt_. If the argument _err_ is non-zero, +and an error occures - it is printed in _s_. + +RETURN VALUE +------------ +The _tep_print_num_field()_ and _tep_print_func_field()_ functions return 1 +on success, -1 in case of an error or 0 if the print buffer _s_ is full. + +EXAMPLE +------- +[source,c] +-- +#include +#include +... +struct tep_handle *tep = tep_alloc(); +... +struct trace_seq seq; +trace_seq_init(&seq); +struct tep_event *event = tep_find_event_by_name(tep, "timer", "hrtimer_start"); +... +void process_record(struct tep_record *record) +{ + struct tep_format_field *field_pid = tep_find_common_field(event, "common_pid"); + + trace_seq_reset(&seq); + + /* Print the value of "common_pid" */ + tep_print_field(&seq, record->data, field_pid); + + /* Print all fields of the "hrtimer_start" event */ + tep_print_fields(&seq, record->data, record->size, event); + + /* Print the value of "expires" field with custom format string */ + tep_print_num_field(&seq, " timer expires in %llu ", event, "expires", record, 0); + + /* Print the address and the name of "function" field with custom format string */ + tep_print_func_field(&seq, " timer function is %s ", event, "function", record, 0); + } + ... +-- + +FILES +----- +[verse] +-- +*event-parse.h* + Header file to include in order to have access to the library APIs. +*trace-seq.h* + Header file to include in order to have access to trace sequences related APIs. + Trace sequences are used to allow a function to call several other functions + to create a string of data to use. +*-ltraceevent* + Linker switch to add when building a program that uses the library. +-- + +SEE ALSO +-------- +_libtraceevent(3)_, _trace-cmd(1)_ + +AUTHOR +------ +[verse] +-- +*Steven Rostedt* , author of *libtraceevent*. +*Tzvetomir Stoyanov* , author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to + +LICENSE +------- +libtraceevent is Free Software licensed under the GNU LGPL 2.1 + +RESOURCES +--------- +https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index 4e768357a30d..966c4b7fd163 100644 --- a/tools/lib/traceevent/event-parse.c +++ b/tools/lib/traceevent/event-parse.c @@ -6402,7 +6402,7 @@ int tep_get_any_field_val(struct trace_seq *s, struct tep_event *event, * @record: The record with the field name. * @err: print default error if failed. * - * Returns: 0 on success, -1 field not found, or 1 if buffer is full. + * Returns: 1 on success, -1 field not found, or 0 if buffer is full. */ int tep_print_num_field(struct trace_seq *s, const char *fmt, struct tep_event *event, const char *name, @@ -6434,7 +6434,7 @@ int tep_print_num_field(struct trace_seq *s, const char *fmt, * @record: The record with the field name. * @err: print default error if failed. * - * Returns: 0 on success, -1 field not found, or 1 if buffer is full. + * Returns: 1 on success, -1 field not found, or 0 if buffer is full. */ int tep_print_func_field(struct trace_seq *s, const char *fmt, struct tep_event *event, const char *name,